Solenoid construction



Aug. 19, 19.41. w. A. RAY ETAL Re. 21,881

I SOLENOID CONSTRUCTION Original Filed Oct. 3, 1932 INVENTORSQ Reissued Aug. 19, 1941 SOLENOID CONSTRUCTION William A. Ray, Glendale, and Charles R. Bay, San Francisco, Calif., assignors to General Controls 00., a corporation of California Original No. 2,096,763, dated October 26, 1531, Serial No. 635386, October 3,- 1932. Application for reissue October 28, 1938, Serial No. 237,489

I V '8 Claims.

This invention relates to a solenoid construction and especially to a solenoid which operates quietly upon alternating current. The solenoid of this invention will be discussed in conjunction with its use as a valve operator, although it can obviously be used as an operator for various units.

Valves adapted to be actuated by an electro-v magnet are common, particularly where direct current or rectified alternating current isavailable. Valves of this character have also been operated with alternating current but they are not satisfactory where substantially silent opera,-

tion is desired due to the continual hum set up' by the alternating current. Also, valves of this character will often stick in open positionafter the current is turned off due to residual magnetism and, as such, can not be depended upon where positive opening and-closing of a valve is required.

The object of the present invention is to generally improve andsimplify the construction and operation of is adapted to be operated on alternating current and in which alternating current hum is entirely eliminated; and further, to provide an electromagnetically actuated valve which is dependable in operation, that is, a'valve which will positively. open when a circuit is made and positively close when a circuit through the valve is broken. The electro-magnetically actuated valve is shown by way of illustration in the accompanying drawing, in which- Figure 1 is a central vertical section through the valve.

Figure 2 is a cross section of the main core.

Figure 3 is a plan view of one of the washers employed in conjunction with the electro-magnet. 7

Referring to the drawing in detail and particularly Figure -1,'A indicates a valve housing provided with an inlet connection 2 and a discharge connection 3. Formed within the valve housing and intermediate the inlet and outlet connections is a valve seat 4 and movable with relation to said seat to open or close the valve is a valve member 5. g

.The movable valve member is, in this instance, actuated by an electromagnet of the solenoid type. The mechanism consists of a base member 6 provided with an extension I which is adapted to be screwed into or otherwise secured with relation to the upper end of the valve housing A. Extending through the extension l and soldered or otherwise secured therein is a tube 8. This electro magnetically actuated valves; to provide a valve of this character which tube is made of a non-magnetic material, such as brass, Monel, or the like, and the upper end is threaded to receive and secure a head member 9 constructed of a magnetic material. Mounted exterior of the tube 8 is a spool ill of non-magnetic material on which is wound a coil I l.

Secured at opposite ends of said spool are iron washers l2 and I3 which are held in place by a sleeve l4 and the head member i'whichacts as a clamping member. k

The magnet as a whole is enclosed by a steel tube l5 which is centered and held in position by an annular shoulder Ii on the base member 6..

A cap or upperhousing member 11 engages the upper end of the tube I5 and this is also centered by an annular shoulder l8. An outlet connection I9 for the reception of a conduit pipe 20 and wires It is formed in the cap II. A handhold 22 is also formed therein and a cover plate 23 normally forms a closure therefor. A screw 24 passes through the cover plate 23 and has threaded engagement with the head member 8.

. This screw functions as a clamping member as it pulls the cover plate and the housing section I] downwardly on the tube It and as such secures it rigidlywith relation to. the base-member 5.

' The wires 2| are connected with the terminals of the coil I l and any suitable means may be employed for making or breaking the circuit therethrough.

The movable valve member is, in the present instance, secured to a plunger generally indicated at 25. This plunger is preferably made of a non-magnetic material such as brass. In the present instance it is made of an aluminum. alloy so as to decrease weight to a minimum. The

plunger carries two. core members which are secured thereto, a main core member indicated at 28 and a central or concentric secondary core member indicated at 21. Both core members are made of iron or steel, the main core member being split throughout its length, as shown in Fig. 2, and so are the washers i2 and I! as shown in Figure 2, the splitting of the same being of importance as it reduces short clrcuited turn losses.

The upper end of the plunger forms a shading coil indicated at 2B. The shading coil is not split as phase displacement of the flux flowing through the central or secondary core is desired with relation to the flow of flux. through the main core, as will hereinafter be described. The upper end of the secondary core member 21 is provided with an annular seat 2! and this is adapted to engage an extension to on the head member 9. The seat formed between the two members is made as acmany installations.

curate as possible, for instance by grinding electromagnetic valves .have been employed on alternating current circuits but that the num or noise produced has rendered them unsuitable for Where valves of this character are used commercially, for instance power plantaiactories, andthe like, hum is of no material importance, but where a valve of this character is installed in conjunction with'a heating furnace, for instance to control the gas flow to a iurnace in a private home, hum can not be tolerated as it is transmitted through the pipes to diiferent rooms in the house and the noise becomes very annoying. The valve shown in the present instance has been particularly constructed to avoid this hum ancialso toavoid sticking oi the valve in open position.

Freedom from any tendency to hum is secured by plunger centering means provided adjacent each end of the plunger. Thus, at the upper end oi the plunger, seat 29 engages extension 90. on

head member 8 while at lower end the plunger rests against and is confined by an .annular i extends to and affects the lower plunger end forthe inter-engagement force of seat 29 and extension 9a is quite positive and of a substantial. ex

tent. Consequently, centering the lower plunger end provides restriction of lateral movement of the lower plunger end. sufficient to limit vibration to an extent such that no hum or other evidence of vibration is apparent. This is accomplished by providing the flange on the valve housing closely. adjacent to the plunger to center this end and thus restrict any lateral movement of the lower end of the plunger.

In actual operation it will be understood that the current flow through the coil ll reaches a maximum flow at the peak of the sine wave and a minimum or a zero flow at the end of each half cycle. Actually there is a large'fiow of current in one direction for a fraction of a second and then this is followed by no flow at the period when the half cycle changes or the current reverses. Under such conditions it is obvious that the plunger 25, which is held in elevated position by the magnetic pull, will remain in full elevated position when the current is flowing and that itwill have a tendency to drop once during each half cycle when there is no current flowing and no magnetic flux produced. The period of non-flow is, of course, so short that the plunger will not actually drop but it does release the grip or pull of the plunger for a fraction of a second and, as such. sets up avibration which is very undesirable due to .the noise transmitted through pipeand conduit connections. This .hum or noise, as previously stated, is overcome in the present instance and will now be described.

otherwise, so as to insure as perfect a seat and When the coil I! is energized the main magnetic circuit or flux flow will pass through the washers l2 and H, the main core member 25 and the outer tube I5. The upper end of the plunger indicated at 28 functions as a shading coil. It is partially in the path of the main flux flow in the core member 26 and'a secondary current is accordingly induced in the shading coil. This current aiiects a phase displacement and at the same time energizes the inner core 21, thus causing it to hold or retain the plunger in open position while the main core member 26 releases, or vice versa. The secondary core member becomes deenergized when the main core member 26 becomesenergized, hence one or the other is constantly holding the plunger, together with the valve 5, in open position and vibration is accordingly entirely eliminated. Furthermore, the amount of iron in member 2] is so small that any residual vmagnetism left after breaking of the circuit throughthe wires 2| can under no circumstances cause the plunger to stick in elevated or open position, hence the moment the circuit through the wire 2| is broken plunger 25 will drop and valve 5 will positively close, thus insuring positive operation which is of great importance particularly where the valve is employed to control the fuel flow to a furnace or the like.

While certain features 'of the present invention are more or less specifically described, we wish it understood that various changes may be resorted to within the scope of the appended claims. Similarly, that the materials and finish of the several parts employed may be such as the manufacturer may decide, oryarying conditions or uses may demand.

We claim:

1. In a device of the character described a coil, magnetic, members positioned at each end of said coil, a plunger, said coil and said members having a passage therethrough for said plunger, a stop member of magnetic material, means positioning said stop in a fixed position with an end thereof projecting into said passage beyond one I of said magnetic members, said plunger comprisnetic member and'of a length substantially sufiicient when said stop member is engaged to bridge said magnetic members.

2. In a device of the character described, a coil, magnetic members positioned at each end of said coil, a plunger, said coil and said members having a passage therethrough for said plunger, a stop member of magnetic material, means positioning said stop in a fixed position with an end thereof projecting into said passage beyond one of said magnetic members, said plunger comprising a non-magnetic member, a magnetic insert engaging said projecting stop end upon movement of said plunger through said passage in one direction to stop said plunger, said non magnetic member enclosing'said insert substantially entirely at its side portion and end away from said stop member, said non-magnetic member extending beyond said projecting end of said stop member when said stop member and said insert are engaged, and an outer. magnetic sleeve substantially surrounding said non-magnetic 3. In a device of the character described, a

coil having a passage therethrough, a stop member of magnetic material fixed in position adjacent one end of said passage, a plunger movable axially through said passage upon electrical energization of said coil to engage said stop member, said plunger comprislnga non-magnetic member, a-magnetic insert, substantially enclosed by said non-magnetic member at its side portion and at the end away from said stop member, and an outer magnetic sleeve substantially surrounding said non-magnetic member, said non-magnetic member, insert, and magnetic sleeve being fixed together as a unit movable as a plunger to engage said insert with said stop member.

4. In a device of the character described, a coil having a' passage therethrough, a magnetic member at each end of said coil, a stop member of magnetic material fixed in position adjacent one end of said passage, a plungermovable axially through said passage upon electrical energization '01 said coil to engage said stop member, said plunger comprising a non-magnetic member, a

magnetic insert; substantially enclosed by said nonmagnetic member at its side portion and at the end away from said stop member. and an outer magnetic sleeve substantially surrounding said non-magnetic member, said sleeve being of ga length substantially sufllcient to bridge the dis- ;tance between the magnetic members ati-the coil ends in one plunger position, said non-magnetic :member, insert, and magnetic sleeve being fixed together as a unit movable as a plunger to engage said insert with said stop member.

5. In a device of the character-described, a coil having a passage therethrough, a stop member of magnetic material fixed in position adjacent one end of said passage and extending into said passage, 9. plunger movable axially through said passage upon electrical energization of said coil to engage said stop member, said plunger comprising anon-magnetic member, a magnetic insert substantially enclosed by said non-magnetic member at its side portion and at the end away from said stop member and recessed at the end adjacent said stop member to receive said stop member below the top of said recessed end, and an outer magnetic sleeve substantially surrounding said non-magnetic member, said non-magnetic member, insert, and magnetic sleeve being fixed together as a unit movable as a plunger to engage said insert with said stop member. 4

6. In a device of the character described, a coil having a passage therethrough, a magnetic member at each end of said coil, a stop member )I magnetic material fixed in position adjacent )ne end of said passage and extending into said passage, a plunger movable axially through said oassage upon electrical energization of said coil :0 engage said stop member, said plunger com- -netic member, insert, and magnetic sleeve .prising a non-magnetic member, a magnetic insert substantially enclosed by said non-magnetic member at its side portion and at the end away from said stop member and recessed at theend adjacent said stop member to receive said stop member below the top of said recessed end, and an outer magnetic sleeve substantially surrounding said non-magnetic member, said sleeve being of a length substantially suflicient to bridge the distance between the magnetic members at the coil ends in one plunger position, said non-magbeing flxed together as a. unit movable as a plunger to engage said insert with said stop member, 7. In an alternating current solenoid, an electro-magnetic coil, a sleeve extending substantially entirely through said coil, a magnetic member supported by the aid of the sleeve adjacent one end of the sleeve, and extending inwardly of the sleeve as well as inwardly of said coil, and terminating near the said end of the sleeve, a core member movable in said sleeve and extending inwardly of the other end of the sleeve for cooperation with said magnetic member, said magnetic 'ember and the core member having cooperating curved surfaces for restraining relative movement between said members when the electromagnetic mil is energized, and a shading coil carried by one of the said members and within said sleeve, said shading coil being in the form of a closed'single turn of uniform section transverse to its axis, and so arranged that at least a portion of the magnetic material oi that member which carries the shading coil, encircles said turn substantially entirely, said shading coil turn being non-intersecting with any portion of the cooperating curved surfaces.

8. In an alternating current solenoid, a wound coil, a sleeve around which the coil is disposed and extending substantially along the entire axial length of said coil, a magnetic member supported by the aid of the sleeve, said magnetic member extending inwardly or said end, said sleeve and with means for permanently attaching said sleeve to an appropriate support, and a shading coil carried by one of said members, and within said sleeve, said shading coil being in the form of a closed single turn, disposed so that its axis coincides with the axis of the member that carries said shading coil, said shading coil turn being non-intersecting with any portion of the cooperating curved surfaces.

. WILLIAM A. RAY. CHARLES R. RAY. 

